This invention relates generally to the provision of refrigeration for use in a chemical processing operation.
Refrigeration is widely required for use in chemical processing operations such as for use in cooling of exothermic reactors and for use in the cooling of crystallizers. The refrigeration may be provided to the chemical processing operation by indirect heat exchange or by direct contact heat exchange. The provision of refrigeration is costly and any improvement in the provision of refrigeration to a chemical processing operation is very desirable. In particular, often in chemical processing, refrigeration is desired at more than one temperature and a system which can better provide refrigeration to a chemical processing operation at more than a single temperature would be very advantageous.
Accordingly, it is an object of this invention to provide an improved system for providing refrigeration to a chemical processing operation.
The above and other objects, which will become apparent to those skilled in the art upon a reading of this disclosure, are attained by the present invention, one aspect of which is:
A method for providing refrigeration for chemical processing:
(A) compressing a refrigerant fluid to produce compressed refrigerant fluid;
(B) cooling a first portion of the compressed refrigerant fluid and passing the cooled first portion of the refrigerant fluid to a chemical processing operation to provide cooling for the chemical processing operation;
(C) cooling a second portion of the compressed refrigerant fluid, turboexpanding the cooled second portion of the refrigerant fluid, and passing the turboexpanded second portion of the refrigerant fluid to the chemical processing operation to provide cooling for the chemical processing operation; and
(D) withdrawing refrigerant fluid from the chemical processing operation and passing refrigerant fluid withdrawn from the chemical processing operation in indirect heat exchange with at least one of the cooling first portion of the compressed refrigerant fluid and the cooling second portion of the compressed refrigerant fluid.
Another aspect of the invention is:
Apparatus for providing refrigeration for chemical processing comprising:
(A) a compressor, a heat exchanger, and means for passing a first refrigerant fluid stream from the compressor to the heat exchanger;
(B) a turboexpander, means for passing a second refrigerant fluid stream from the compressor to the heat exchanger, and means for passing the second refrigerant fluid stream from the heat exchanger to the turboexpander;
(C) a chemical processing operation, means for passing the first refrigerant fluid stream from the heat exchanger to the chemical processing operation, and means for passing the second refrigerant fluid stream from the turboexpander to the chemical processing operation; and
(D) means for passing refrigerant fluid from the chemical processing operation to the heat exchanger.